chem test 2

A sample of gas contains four gases with the following partial pressures: He (113 mm Hg), Ne (184 mm Hg), Ar (35 mm Hg), and Xe (445 mm Hg). What is the total pressure of the sample? A. 777 mm Hg B. 760. mm Hg C. 445 mm Hg D. 332 mm Hg

A

A sample of neon gas has a volume of 5.0 mL at a pressure of 1.50 atm. What is the pressure exerted by the gas if the volume is increased to 30.0 mL, at constant temperature? A. 0.25 atm B. 9.0 atm C. 1.5 atm D. 0.21 atm E. 7.5 atm

A

Butane, CH3CH2CH2CH3, has the structure shown below. What is the strongest type of intermolecular force that exists between two butane molecules? A. London dispersion forces B. Hydrogen bonding C. Temporary dipole interactions D. Dipole-dipole interactions

A

Consider the two liquids A and B shown in closed containers. Which liquid exhibits the stronger intermolecular forces? A. Liquid A B. Liquid B C. Both Liquids A and B have equal vapor pressures. D. Not enough information is given.

A

A 54.2 L sample of gas at 115 K is heated to 345 K, at constant pressure. What volume does the gas now occupy? A. 2.15 × 106 L B. 163 L C. 18.1 L D. 732 L

B

A gas cylinder containing neon has a pressure of 491 mm Hg at 295 K. If 322 mm Hg of helium and 75 mm Hg of argon are added to this cylinder, at constant temperature and volume, what will be the pressure in the cylinder? A. 1183 mm Hg B. 888 mm Hg C. 813 mm Hg D. 88.8 mm Hg

B

An aerosol can has a pressure of 1.86 atm. What is this pressure expressed in units of mm Hg? A. 1.86 mm Hg B. 1410 mm Hg C. 1860 mm Hg D. 0.00245 mm Hg

B

Consider the two liquids A and B shown in closed containers. Which liquid has the higher vapor pressure? A. Liquid A B. Liquid B C. Both Liquids A and B have equal vapor pressures. D. Not enough information is given.

B

Propanol, CH3CH2CH2OH, has the structure shown below. What is the strongest type of intermolecular force that exists between two propanol molecules? A. London dispersion forces B. Hydrogen bonding C. Temporary dipole interactions D. Dipole-dipole interactions

B

The normal boiling point of a liquid is the temperature at which its vapor pressure equals which of the following? A. 1 mm Hg B. 760 mm Hg C. The pressure above the liquid D. The vapor pressure of water

B

Which gas law describes the relationship between the volume and temperature of a sample of gas at constant pressure? A. Boyle's law B. Charles's law C. Gay-Lussac's law D. Avogadro's law E. Dalton's law

B

Which phase change below is endothermic? A. Deposition B. Melting C. Condensation D. Freezing

B

A patient's systolic pressure is measured as 128 mm Hg. What is this pressure in units of atm? A. 128 atm B. 1.28 atm C. 0.168 atm D. 9.73 x 104 atm E. 8.71 atm

C

A scuba diver typically begins a dive with a compressed air tank at 2,350 psi. What is this pressure expressed in units of mm Hg? A. 160. mm Hg B. 3.09 mm Hg C. 1.21 × 105 mm Hg D. 1.79 × 106 mm Hg E. 45.5 mm Hg

C

An aerosol spray can with a volume of 350 mL registers a pressure of 4.5 atm at room temperature. What happens to the pressure of the gas inside the can if the can is stored outside during the winter months? A. The pressure of the gas will remain at 4.5 atm. B. The pressure of the gas will be greater than 4.5 atm. C. The pressure of the gas will be less than 4.5 atm. D. It is impossible to predict without knowing the amount of gas present inside the can.

C

How many moles are contained in 5.33 L of O2 at standard temperature and pressure? A. 5.33 mol of O2 B. 1.00 mol of O2 C. 0.238 mol of O2 D. 22.4 mol of O2 E. 4.20 mol of O2

C

How many moles of gas are contained in a scuba diver's 12.6-L tank filled with 3422 psi of air at 25 °C? A. 1760 moles B. 2.10 × 104 moles C. 120. moles D. 1430 moles

C

The temperature of a 0.750-L gas sample at 25 °C and 2.00 atm is changed to 250 °C. What is the final pressure of the system, at constant volume? A. 20.0 atm B. 0.200 atm C. 3.51 atm D. 0.427 atm

C

Three of the four phase changes below are endothermic. Which phase change is NOT endothermic? A. Vaporization B. Sublimation C. Condensation D. Melting

C

Which molecule(s) exhibit hydrogen bonding? A. H2S B. CH4 C. NH3 D. HCl E. All of the molecules exhibit London dispersion forces.

C

When octane evaporates, what kind of attractive forces are overcome? A. Covalent bonding between carbon and hydrogen atoms B. Hydrogen bonding between octane molecules C. Dipole-dipole interactions between octane molecules D. London dispersion forces between octane molecules

D

Which assumption is NOT part of the kinetic-molecular theory of gases? A. A gas consists of particles that move randomly and rapidly. B. The size of gas particles is small compared to the space between the particles. C. Because the space between gas particles is large, gas particles exert no attractive forces on each other. D. The kinetic energy of gas particles does not change with increasing temperature. E. When gas particles collide with each other, they rebound and travel in new directions.

D

Which molecule(s) exhibit hydrogen bonding? A. CH4 B. CHCl3 C. NF3 D. HF E. All of the molecules exhibit hydrogen bonding.

D

Which cylinder at STP will contain the greatest number of gas particles? A. a 5.0-L cylinder of neon B. a 5.0-L cylinder of helium C. a 5.0-L cylinder of nitrogen D. a 5.0-L cylinder of hydrogen E. All of the cylinders contain the same number of gas particles.

E

Which molecule(s) exhibit London dispersion forces? A. Kl B. CH4 C. NH3 D. HBr E. All of the molecules exhibit London dispersion forces.

E